'outbound' originates from Middle English, specifically the words 'out' and 'bound', where 'out' meant 'outside' and 'bound' meant 'ready to go'.

'Outbound' changed from the Middle English phrase 'out bunden' and eventually became the modern English word 'outbound'.

Initially, it meant 'ready to go outside', but over time it evolved into its current meaning of 'traveling away from a particular place'.